It's simple,  Data is only as valuable as, and as long as - the data has integrity and is representative of a real-world application.
  - Want out?  Change your info. Contaminate the data.  Pollute the archives with near-accurate but fictional info.  Change it often, anonymizing and obfuscating the truth.
Change your zipcode.  Change your e-mail address to a throwaway Yahoo! or Hotmail edress.
Change your age to 11.
  Let them datamine.
    Privacy is a fading Illusion,
            but Heisenberg was right.
  Oh - and never forget to read the Fine Print BEFORE you sign up.